Generally, a toilet bowl used for both urination and stool consisted of a ceramic bowl as a main body and a flushing water tank as a reservoir disposed at the back of the main body. The conventional toilet bowl adopts the method that a certain amount of water must be filled in the water tank to completely flush out the contents of the toilet bowl.
Recently, an improved automatic toilet system has been introduced for installation in modern public buildings. The automatic toilet bowl adopts the control system, which has an infrared sensor to detect occupancy of the toilet and to transmit the sensed signal to the main control unit for operating a solenoid valve connected to a flushing valve installed in the toilet bowl.
As shown in FIG. 1, another method is introduced for flushing the bowl in which an infrared sensor (1) installed on the cover of the toilet bowl senses occupancy of the toilet and a main control unit (2) for processing the sensed signal and a motor (3) for lifting a siphon cover vertically by means of a connected chain.
The conventional solenoid valve applied to the flushing system requires high water pressure in the water supply line. Therefore, it is possible to use a pilot type of solenoid valve in the public buildings, which is operable in the high water pressure with low power consumption. On the contrary, it is difficult to use a solenoid valve for the common toilet bowl with a back water tank used in residences because the water pressure in the residential water supply line is relatively low.
Especially, a direct-operating type of one-inch diameter solenoid valve is developed and currently produced for installation in residential bathrooms, which has relatively lower water pressure and flow rate. However, this type of valve has a disadvantage in that it takes relatively longer to operate and does not properly dispose of the contents because of the low water pressure and low flow rate.
Further, some conventional toilet bowl employ a motor for forcibly supplying the proper amount of water. However this system has the disadvantage of a complicated linkage mechanism. Because the motor is operated in a damp environment, the durability of the motor is always problem.